Automatic control device for elevators.



L. J. MILKE. AUTOMATIC CONTROL DEVIGBFOR ELEVATORS. APPLICATION FILED MAY 23, 1908. 923,366. Patented June 1, 1909.

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WITNESSES 12v VENTOR L. J. MILKE. AUTOMATIC GONTROL DEVICE FOR ELEVATORS.

APPLICATION FILED MAY 23, 1908. 923,366, Patented June 1, 1909'.

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UNTTE STATES PATENT LOUIS J. MILKE, OF BALTIMORE, MARYLAND.

AUTOMATIC CONTROL DEVICE FOR ELEVATORS.

To all whom it may concern:

Be it known that I, LOUIS J. MILKE, a citizen of the United States, residing at Baltimore city, State of Maryland, have invented certain new and useful Improvements in Automatic Control Devices for Elevators, of which the following is a specification.

My invention relates to automatic control devices for elevators, and has for its object means by which the operation of the elevator is automatically controlled by the opening and closing of the elevator door.

The device has for its particular object to prevent the starting of the car while the door is open.

The device is so constructed that after the car has been stopped at a landing and the door has been opened, it is impossible to again start the car without the door first having been closed, thereby lessening to a degree the possibility of accident to a passenger in entering or leaving the car, occasioned by the premature starting of the car.

With the foregoing object in view, my invention consists in certain novel features of construction and combinations of parts which will be hereinafter described and pointed out in the claims.

In the accompanying drawings, Figure 1, is an elevation of part of an elevator shaft equipped with my invention; Fig. 2, is a sectional view through the operating valves showing same in position for operating the elevator; Fig. 3 is a similar view some of the parts being in opposite positions from those shown in Fig. 2, and Fig. 4, is a diagrammatical view showing the location of the gate valve in relation to the parts now in use in the ordinary hydraulic elevators.

Reference being had to the drawings, A indicates the elevator door, and as viewed in Fig. 1, one is closed and one in open position. Fulcrumed at 1 to some fixed portion of the wall of the elevator shaft is a bell crank lever 2, there being one supplied for each door at each landing throughout the shaft; the short crank of this bell crank lever is arranged in the path of the door and is engaged thereby as the door is closed.

Attached to the long end of the lever 2 is one end of a tension spring 3, the opposite Specification of Letters Patent.

Application filed May 23, 1908.

Patented June 1, 1909.

Serial No. 434,658.

end of the spring being fixed to some permanent support. Passing through the long end of the lever is a line of cable 4, having mounted thereon a series of stops 5, one of these stops being provided and located above each of the levers 2. The lower end of the cable 4 is attached to the stem 6, carrying spaced pistons 8 and 9 working in the cylinder 7. The cylinder 7 is open at both ends and may be provided at the bottom with lugs 10, and at the top with a screw cap with an inwardly extending flange 11, serving to limit the movement of the piston in the other direction. Connected with the cylinder is a feed pipe 12 conveying thereto from a supply reservoir 13, fluid under pressure for the operation of the gate Valve C controlling passage of fluid, under pressure, from the reservoir B to the hoisting-piston F-of the elevator. The stem 13 of the said valve is prolonged and constitutes the piston rod of the piston 14 fitted within the cylinder 15. Connecting the said cylinder with the cylinder 7 are two pipes 16 and 17.

Secured to the stem 6 is a weight 18, the cable 4- passing therefrom upwardly through the levers 2 and over a pulley 19 and having attached to its free end a weight 20.

Although it may be found desirable to attach the gate valve C at some point other than that as shown, it is shown in the present instance diagrammatically in Fig. 4 as attached to a pipe D leading from the conductors operating valve E to the hoisting piston F.

My device is operated as follows :Assuming that the elevator door A is closed as shown in the upper partof Fig. 1, the door is then in contact with the short arm of the bell crank lever 2, the long arm of which is forced downward and out of contact with the stop 5 on the cable 4, and by means of the weight 18 on the stem 6, the pistons S and 9 in the cylinder 7 are forced downward and occupy the position as shown in Fig. 2, and when in this position fluid under pressure from the storage reservoir B flows through pipe 12 through cylinder 7, through pipe 17 into cylinder 15, under piston 14 to which is secured the piston rod 13, causing the piston to ascend, thereby opening the gate valve C, permitting the car to be freely operated. Assuming contrary to the above, the elevator door being open as shown in the lower part of Fig. 1, the contact previously maintained between the door and the short arm of the bell crank lever 2 is broken with the result that the tension, which spring 3 was under while the door remained closed is released, with the result that the long arm of the bell crank lever 2 is raised and brought into contact with the stop 5 011 the cable 4, thereby causing the piston rod 6 to ascend, also causing the pistons 8 and 9 to ascend in the cylinder 7, as shown in Fig. 3; and when in this position the fluid under pressure from the storage reservoir B flows through pipe 12,

through the cylinder 7, where it is directed through pipe 16, into the cylinder 15, and on top of piston 14, causing the piston rod 13 forming a stem of the gate valve C to descend and close the said gate valve, thereby cutting off the pressure by which the car is operated, and rendering further operation of the car impossible. I

It will be noted when the elevator door A is closed and the gate valve opened that the piston 1 in the cylinder is made to ascend and the pistons 8 and 9 to descend and in so doing the fluid in the cylinder above the said piston is discharged through pipe 16 into the cylinder 7 above the piston 8 and is discharged through the upper open end of the said cylinder, this takes place si- ,multaneously with the entrance of fluid into the cylinder under the piston 14:, through pipe 17, the lower end of the cylinder 7 being closed by the piston 9 and the upper end opened by the descent of piston 8.

It will be readily seen that when the elevator door is opened and the gate valve closed, the pistons 8 and 9 are made to ascend, the upper end of the cylinder 7 is closed and the lower end opened, consequently the fluid passes through the cylinder 7, thence through pipe 16 into the cylinder 15 above the piston 14 causing the piston 14: to descend and the liquid below the said piston is discharged through pipe 17 into the cylinder 7 below the piston 9 therein and out through the lower open end thereof.

Slight changes and alterations might be resorted to in the form and arrangement of the several parts described within the scope of the appended claims without departing from the spirit and scope of my invention, hence I do not desire to limit myself to the exact construction as herein set forth: but

Having fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. An elevator safety-device, comprising the combination with an elevator-door, of a bell-crank lever fulcrumed in the path thereof and engaged thereby When the same is the door is opened, thereby to elevate said cable, means for causing said cable to resume its original position when the arm 'of the lever is disengaged from said stop; gatevalve mechanism governing the passage of fluid under pressure to the usual hoistingpiston of the elevator; a supply-reservoir for the fluid under pressure; and valve-mechanism intermediate said reservoir and said gate-valve mechanism and controlled by the movement of said cable to open and close said gatevalve.

2. An elevator safety-device, comprising the combination with an elevator-door, of a bell-crank lever fulcrumed in the path thereof and engaged thereby when the same is closed, a tension-spring connected to said lever and operating to rock the same upward on its fulcrum when the door is opened, a cable arranged in the path of said lever and carrying a stop in proximity thereto and directly engaged by one arm thereof when the door is opened, thereby to elevate said cable, means for causing said cable to resume its original position when the arm of the lever is disengaged from-said stop; gate valve mechanism governing the passage of fluid under pressure to the usual hoistingpiston-of the elevator; a supply-reservior for the fluid under pressure; and valveunechanism intermediate said reservoir and said gate-valve mechanism and controlled by the movement of said cable to open and close said gate-valve, said intermediate valvemechanism comprising two communicating cylinders, a double piston in one cylinder, having a piston rod connected to said cable, and a single piston in the other cylinder.

3. An elevator safety-device, comprising the combination with an elevator-door, of a bell-crank lever fulcrumed in the path thereof and engaged thereby when the same is closed, a tension-spring connected to said lever and operating to rock the same upward on its fulcrum when the door is opened, a cable arranged in the path of said lever and carrying a stop in proximity thereto and directly engaged by one arm thereof when the door is opened, thereby to elevate said cable, means for causing said cable to resume its original position when the arm of the lever is disengaged from said stop; gate valve mechanism governing the passage of fluid under pressure to the usual hoisting-piston of the elevator; a supplyreservoir for the fluid under pressure; and

open and close said gate-valve, said intermediate valve -mecl1anism comprising two communicating cylinders, a double piston in one cylinder, having a piston-rod connected to said cable, and a single piston in the other cylinder, said gate-valve and said single piston having a common operating-rod.

In testimony whereof I afiiX my signature in presence of two Witnesses.

LOUIS J. MILKE,

Witnesses E. \VALTON BREWINGTON, E. WALTER RoBINsoN. 

